Bowling ball refinishing machine

ABSTRACT

A machine for restoring the sphericity of used bowling balls in which a bowling ball is held in a vacuum chuck and rotated about a vertical axis passing through the center of the ball. A cutter is moved through an arcuate path in a vertical plane which includes the vertical axis of rotation, the cutter being moved in a circular path about a horizontal axis through the center of the ball. After the major upper portion of the ball has been cut, the ball is removed from the chuck, inverted and reseated in the chuck. The chuck is elevated and the remainder of the surface of the ball is cut as before.

United States Patent 1191 [111 3,714,703 Maples 1 1 Feb. 6, 1973 54] BOWLING BALL REFINISHING 3,289,354 12/1966 Stevens etal ....51/289 s x MA HINE 3,079,732 3/1963 Rawstron et al ..82/12 x lnventor: Travis N. Maples, 1326 E. Country Club Road, Roswell, N. Mex. 88201 Filed: May 27, 1970 Appl. No.: 40,855

References Cited UNITED STATES PATENTS Tenney ..82/12 X Sammons et a1. ..408/97 Schroeder, Jr.

Primary Examiner-Andrew R. Juhasz Assistant ExaminerZ. R. Bilinsky Att0rneyMellin, Moore & Weissenberger [57 ABSTRACT A machine for restoring the sphericity of used bowling balls in which a bowling ball is held in a vacuum chuck and rotated about a vertical axis passing through the center of the ball. A cutter is moved through an arcuate path in a vertical plane which includes the vertical axis of rotation, the cutter being moved in a circular path about a horizontal axis through the center of the ball. After the major upper portion of the ball has been cut, the ball is removed from the chuck, inverted and reseated in the chuck. The chuck is elevated and the remainder of the surface of the ball is cut as before.

8 Claims, 9 Drawing Figures mlllllllllllll PATENTEDFEB ems 3.7141763 sum 10F 4 k\\$ll l Ill/111m F IG l INVENTOR TRAVIS N. MAPLES BY ATTORNEYS PAIENIEn FEB s 1915 3. 714.7 03

TRAVIS N. MAPLES ATTORNEYS PATENTED FEB 6 I975 SHEET 30F 4 INVENTOR.

TRAVIS N. MAPLES m WW,

ATTORNEYS mammm' 6 ms 3.714.703 SHEEI u 0F 4 FIG 9 I'NVENTOR. TRAVIS N. MAPLES ATTORNEYS 1 BOWLING BALLREFINISI'IING MACHINE BACKGROUND OF THE INVENTION One of the most important aspects of a satisfactory bowling ball is the trueness of its spherical shape. In the use of the ball, the rolling contact of the ball with the alley is localized about an axis determined by the location of the finger holes and the manner of delivery by the bowler. As the ball is used, the surface contacting the alley will gradually wear so that the ball becomes slightly ellipsoidal in shape. Even a very small degree of ellipticity (which may well be imperceptible to the unaided eye) will result in an undesirable loss of trueness in the roll of the ball. In addition, normal usage of bowling balls often results in denting thereof, which again may adversely affect the roll of the ball. This wear and tear is particularly aggravated on bowling balls kept by alleys for the general use of the public.

If the relatively small amount of the unworn surface of the ball could be removed so that the ball would again be spherical, the difference in weight and feel of the ball would be, for all practical purposes, unnoticeable to the bowler. However, applicant is unaware of any machine that is presently available which can be used to refinish a bowling ball and restore it to its original spherical shape. Thus, when a bowling ball loses sufficient of its shape as to noticeably affect the trueness of its roll, the owner of the ball has no alternative but to discard the ball and buy a new one.

It is the principal object of the present invention to provide a machine for refinishing a worn bowling ball and restoring it to a spherical shape;

It is also an object of the invention to produce a single machine that is capable of being used to restore the spherical shape of the ball, to aid in the proper drilling of finger holes into the ball, and which is capable of being used to finish and polish the ball.

It is a further object to provide such a machine that will be sufficiently inexpensive to build and use so that the cost of refinishing a ball will be substantially less than the cost of buying a new ball.

Still another object of the invention is to provide such a machine as will be easy to use by relatively unskilled operators. Such an object is important since the major use of such machines would be by bowling alley operators. If a highly skilled technician were required, the use of the machine would in many instances be economically unjustifiable.

Other objects and advantages will become apparent in the course of the following detailed description.

SUMMARY OF THE INVENTION The machine of the present invention comprises a vertical chuck to hold a bowling ball. The chuck is connected to a vacuum source so that the ball is held'firmly by the chuck without any injury or marring of the surface thereof. The chuck is rotated to rotate the ball A cutting tool is mounted on the machine for moveabout a vertical axis passing through the ball.

ment in a vertical plane at a fixed distance from a horizontal axis passing through the center of the ball.

As the ball is rotated, the cutter gradually moves up chuck and ball are adjusted vertically so that the center of the newly finished portion is again exactly on the machine can also be used to drill finger holes inthe ball.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, forming a part of this application I and in which like parts are designated by like reference numerals throughout the same,

FIG. 1 is a front elevational view of a bowling ball refinishing machine constructed in accordance with the invention, with portions thereof shown in section,

FIG. 2 is a side elevational view of the upper part of I the machine of FIG. 1,

FIG. 3 is a plan view of the machine of FIG. 1,

FIG. 4 is a side elevational view of the upper portion of the machine of FIG. 1, showing it set up for the drilling of finger holes in the bowling ball,

FIG. 5 is a sectional detail of the hole-drilling bit guide of FIG. 4,

FIG. 6 is a sectional view of a finishing tool for use with the machine,

FIG. 7 is an end view of-the finishing tool of FIG. 6,

FIG. 8 is a sectional view of a polishing tool for use with the machine,

FIG. 9 is an end view of the polishing tool of FIG. 8.

DESCRIPTION OF THE preferred EMBODIMENT A semi-circular, n'gid radius arm 15 is provided at its ends withstubs 16 which are supported in bearings 17 in support arms 12 and 13 so that the radius arm 15 may rotate about a horizontal axis defined by the stubs 16. Bearings 17 are preferably oil-lite bronze bearings, but other types of bearings may be used, as long as the bearings between the radius arm stubs and the support arms are as free from axial and radial play as possible.

Gear 18, fixed to radius arm 15, is driven by gear 19 'rotatably powered by motor 20, which is mounted on support arm 13.

Carried by the radius arm 15, centrally thereof, is tool holder 21, fixed to arm 15 by screw 22. A cutting bit 23 is carried by tool holder 21, and a micrometer 24 is provided to adjust the position of the cutting surface 25 of bit 23 and thereby regulate the depth of cut on the surface of the bowling ball. A look nut 26 may be utilized to lock the depth adjustment of the bit.

The bowling ball 14 is carried by the cup-shaped vacuum chuck 28, which has an elastomeric O-ring 29 disposed in and around the upper face of the circular rim 30 of the chuck to provide an air-tight seal between I the ball and the chuck. The rim 30 is horizontal so that the center of a ball placed on the rim will be in line with the axis of the chuck. The interior of the cup of the chuck is adapted to be maintained at a subatmospheric pressure by the communication of the chuck through the central passage 31 in the chuck shank 32 which is connected by a conventional rotatable coupling 33 and air line 34 to a suitable vacuum source 35.

l The chuck shank 32 is rotatably mounted, by ball bearings 36 and 37, in shank holder 38 for rotation about a vertical axis which intersects the horizontal axis of radius arm 15. The shank holder 38 is provided with a finely threaded portion 39 threaded through frame 1 1 so that the height of the chuck 28 may be adjusted by a rotation of the shank holder relative to the frame. The radial flange 40 at the upper end of the shank holder is preferably calibrated on its upper surface to serve as a height adjustment indicator. Lock nut 41, with integral handle 42 extending therefrom, is threaded on the thread of the shank holder and is adapted to be screwed down thereon against the frame 11 to lock the shank holder after the height of the chuck has been adjusted.

Fixed to the lower end of chuck shank 32 is spur gear 43 which is in mesh with spur gear 44 driven by the frame-mounted motor 48. The axes of gears 43 and 44 are parallel and the teeth thereof are of sufficient width as to enablegear 43 to move up or down with chuck shank 32 and remain in meshing engagement with gear Support arm 13 is provided with an opening reversible type so that the cutting tool movement can be reversed after the aforementioned cut'is made, or at 1 any time the operator deems advisable.

Bowling balls are customarily made of hard rubber or plastic and a preferable speed of rotation of the chuck is in the order of 500 rpm. to produce the proper cutting action. If desired, a suitable variable speed control may be utilized to regulate variable speed motor 48 so that the linear speed of the surface of the ball past the cutter 23 will be substantially constant for all positions of the cutter relative to the surface of the ball. For this purpose a potentiometer 55 may-be mounted on support arm 12 for actuation by radius arm stub 16.

The amount of resistance of the potentiometer will thus be a'function of the position of the radius arm and can be used in a conventional speed control circuit. The

therethrough to receive the mounting shaft 49 of a standard feeler gauge 50. This gauge has an indicating needle 51 and a feeler member 52, and the opening through the support arm is preferably oriented so that the axis of the mounting shaft 49 intersects the horizontal axis of the radius arm 15 and the vertical axis of chuck 28. A set screw 53, with handle 54, is provided to releasably lock the mounting shaft 49 to the support .arm 13.

1n the operation of the machine thus far described, the feeler gauge 50 is moved out of the way, generally to the position shown in FIG. 1, and the cutting bit 23 is retracted awayfrom the center of the machine. A

bowling ball 14 is then placed on vacuum chuck 28 and the vacuum source 35 is energized to seat the ball firmly on the chuck. The frictional engagement of the ball and-the rubber O-ring 29 will aidin restraining rotation of the ball relative to thechuck. In order tov ball. The radius arm drive motor 20 is then energized-to drive the radius arm at arelatively slow speed through itspath of movement, which is from about three fourths of the way down the ball to slightly past the top of the ball. This movement of the cutting bit in a vertical plane which includes the vertical axis of rotation of the ball andchuck, and in an arcuate path having the horizontal axis of the radius arm as its center, will cut the upper three fourths of the surface of the ball completely and produce a surface on the ball which is equidistant at all points from the center defined by the intersection of the aforementioned vertical and horizontal axes. The motor 20 is preferably of the speed of rotation of the radius arm 15 is sufficiently slow so that the cutter carried therebywill cut the en- I tire surface of the ball. Typically, it will take about 7 minutes to travel through its cutting path.

After the upper surface of the ball has been cut, the

radius arm 15 is moved to a position so that the cutting tool is somewhat above the center of the ball, and drive motors lit and 48 are de-energized. The feeler gauge shaft 49 is loosened and is slid up in the support arm 13 so that the feeler 52 engages the cut surface of the ball sufficiently to produce a movement of the feeler gauge 7 indicating needle 51. Set screw 53 is then tightened to clamp the feeler gauge rigidly to the support arm, and

the reading of the feeler gauge is noted.

-The vacuum source is de-energized, allowing the ball 14 to be removed from the chuck. After inverting the ball so-that the uncut surface is now on top, the ball is again seated on the chuck and the vacuum source is energized. Since the previously cut surface of the ball is now seated on the chuck, the center of the cut surface will be below the axis of the radius arm 15 by an amount equal to the portion removed and the cut surface of the ball will-nowengage and depress the feeler of the feeler gauge 50 to a greater degree. The chuck shank holder 38 is then rotated in frame 11 in a direction to elevate the chuck and ball until the feeler gauge needle indicates the previously noted reading, and the lock nut 41 is tightened to lock the chuck and ball at this height. The center of the previously cut surface of the ball will now be exactly on the horizontal axis of the radius arm 15.

The feeler gauge is then moved downwardly away from the ball. Drive motors 48 and 20 are again energized to rotate the ball and to move the cutting tool ,upwardly to cut the remaining surface of the ball. After this cut, the entire surface of the ball will have been cut and the ball will be perfectly spherical.

In some instances, it is desirable to plug the original 7 finger holes and to drill new holes at desired locations. If so, the cutting tool holder 21 is removed from radius arm 15, and the tool holder is mounted thereon, as illustrated in FIG. 4. As best seen in FIG. '5, tool holder 60 comprises a body member 61 havinga bifurcated end straddling the radius arm 15 and secured thereto by screw 62. The body member has an opening 63 thcrethrough aligned with the center of the bowling ball, and .adapted to receive a circular bushing 64 thereinto. Bushing 64 may have a drill guide bore 65 coaxial with the bushing if holes are tobe drilled in the direction of the inclined hole may be varied, after.

which the adjustment set screw 66 is tightened to firmly fix the bushing 64 in the body member opening 63.

The radius arm, with the drill bit guide attached thereto, is moved to the desired position relative to theball surface. The gear 18. fixed to the radius arm is preferably calibrated, as indicated in FIG. 4, to aid in the proper location of the drill bit guide. A suitable bushing 64 is used, a drill bit 67 is inserted through the bushing and the desired hole is drilled into the ball. After drilling, the radius arm is moved to the next desired position and the next hole is drilled. The third hole-is drilled in the same manner.

The machine may then be used to finish the cut surface of the ball and remove any lathe marks therefrom. The drill bit guide bushing 64 is removed from too] holder 60, and the finishing tool 70, FIGS. 6 and 7, is inserted therein. Finishing tool 70 comprises an annular outer sleeve 71 adapted to fit within tool holder opening 63 and an inner sleeve member 72 having an annular portion 73 telescopically fitting into sleeve 71. A carborundum mesh screen 74'is fitted onto the end of the inner sleeve member 72 and held in place by retainer ring 75. A ripple spring 76 is disposed between the sleeve members 71 and 72. The outer sleeve member 71 is axially positioned in the tool holder so that the ripple spring biases the inner sleeve member against the surface of ball 14 with the desired pressure and set screw 66 is tightened to lock sleeve member 71 to the-tool holder. The interior of the finishing tool 70 is preferably connected to a vacuum source to draw the dust therefrom during the finishing operation.

After the finishing tool 70 is positioned in the tool holder, drive motors 48 and 20 are again energized and the Carborundum mesh screen is passed over the entire surface ,of the ball in the same manner as described in the cutting operation. Using the machine 10 for this purpose will ensure that the ball surface is uniformly finished over the entire surface thereof.

Preferably, several passes over the ball surface will relatively unskilled operator to produce a refinished ball of a sphericity and finish comparable to that of a new ball. I 1

Having thus described my invention, 1 claim: 1. A bowling ball refinishing machine comprising: a. a frame including a pair of spaced-apart upstanding support arms; b. a chuck holder disposed between said support arms and mounted in said frame for vertical-adjustment relative to said frame,

. means for locking said chuck holder to said frame at a desired vertical adjustment relative thereto to prevent movement of said chuck holder relative to said frame; y a cup-shaped chuck mounted in said chuck holder for rotation about a vertical axis, the rim of said chuck being horizontal and adapted to engage the ball in air-tight engagement therewith; means for placing the interior of said cup-shaped chuck at a subatmospheric pressure;

f. means for rotating said chuck;

g. a radius arm journaled at one end thereof in one of said support arms and journaled at the other end in the other of said support arms, said radius arm being journaled in said arms for rotation about a horizontal axis passing through the vertical axis of said chuck;

h. a tool holder rigidly mounted on said radius arm centrally thereof;

i. a tool darried in said tool holder for engagement with the surface of a ball held in said chuck; and

j. means for rotating said radius arm about said horizontal axis to move said tool holder from a vertical position to a position substantially below said horizontal axis.

2. A machine as set forth in claim 1, wherein said tool is a cutting bit, and further including means carried by said tool holder for fixedly adjusting the distance of said cutting bit from said horizontal axis.

3. A machine as set forth in claim 2 and further includinga feeler gauge mounted in said frame below be made, utilizing finishing tools having progressively Y finer mesh screens.

After the surface of the ball has been finished,-the surface of the ball may be polished by the polishing tool 80 of FIGS. 8 and 9. This tool has an annular sleeve portion 81 adapted to fit telescopically within sleeve member 71 and to be biased relatively thereto by ripple spring 76. The end of sleeve portion 81 is provided with perforated plate 82 against which felt blocks 83 seat. The blocks are separated and held in place by corrugated springs 84. The outer blocks 83 are preferably of a coarser felt material than the central block. The surfaces 85 of the blocks are shaped on a radius to fit flush against the surface of ball 14. The interior of polishing tool 80 is preferably connected to a vacuum source to remove dust.

The polishing operation is the same as described in connection with the finishing operation.

As is apparent from the foregoing, all of the abovedescribed operations may be carried out easily by a said horizontal axis and having an upwardly directed feeler member adapted to engage the lower surface of a ball held in said chuck at a point thereon above the lower limit of travel of said cutting bit.

4. A machine as set forth in claim 1, wherein said tool holder on said radius arm includes a tool-receiving opening therethrough, the axis of said opening being directed'toward the surface of a ball held in said chuck and wherein said tool is disposed in said opening and extends therefrom towards the surface of said ball, said tool being axially movable in said tool holder opening.

5. A machine asset forth in claim 4; wherein said tool is a cutting bit, and further including means carried by said tool holder for fixing said cutting bit relative to said tool holder to prevent axial movement of said said tool holder opening, said bushing having a 'bore therethrough, the axis of said bore being at a predetermined angle relative to the axis of said opening, and

wherein said tool is a rotatable drill bit extending axially through said bushing bore.

4 a IF I i 

1. A bowling ball refinishing machine comprising: a. a frame including a pair of spaced-apart upstanding support arms; b. a chuck holder disposed between said support arms and mounted in said frame for vertical adjustment relative to said frame, c. means for locking said chuck holder to said frame at a desired vertical adjustment relative thereto to prevent movement of said chuck holder relative to said frame; d. a cup-shaped chuck mounted in said chuck holder for rotation about a vertical axis, the rim of said chuck being horizontal and adapted to engage the ball in air-tight engagement therewith; e. means for placing the interior of said cup-shaped chuck at a subatmospheric pressure; f. means for rotating said chuck; g. a radius arm journaled at one end thereof in one of said support arms and journaled at the other end in the other of said support arms, said radius arm being journaled in said arms for rotation about a horizontal axis passing through the vertical axis of said chuck; h. a tool holder rigidly mounted on said radius arm centrally thereof; i. a tool carried in said tool holder for engagement with the surface of a ball held in said chuck; and j. means for rotating said radius arm about said horizontal axis to move said tool holder from a vertical position to a position substantially below said horizontal axis.
 1. A bowling ball refinishing machine comprising: a. a frame including a pair of spaced-apart upstanding support arms; b. a chuck holder disposed between said support arms and mounted in said frame for vertical adjustment relative to said frame, c. means for locking said chuck holder to said frame at a desired vertical adjustment relative thereto to prevent movement of said chuck holder relative to said frame; d. a cup-shaped chuck mounted in said chuck holder for rotation about a vertical axis, the rim of said chuck being horizontal and adapted to engage the ball in air-tight engagement therewith; e. means for placing the interior of said cup-shaped chuck at a subatmospheric pressure; f. means for rotating said chuck; g. a radius arm journaled at one end thereof in one of said support arms and journaled at the other end in the other of said support arms, said radius arm being journaled in said arms for rotation about a horizontal axis passing through the vertical axis of said chuck; h. a tool holder rigidly mounted on said radius arm centrally thereof; i. a tool carried in said tool holder for engagement with the surface of a ball held in said chuck; and j. means for rotating said radius arm about said horizontal axis to move said tool holder from a vertical position to a position substantially below said horizontal axis.
 2. A machine as set forth in claim 1, wherein said tool is a cutting bit, and further including means carried by said tool holder for fixedly adjusting the distance of said cutting bit from said horizontal axis.
 3. A machine as set forth in claim 2 and further including a feeler gauge mounted in said frame below said horizontal axis and Having an upwardly directed feeler member adapted to engage the lower surface of a ball held in said chuck at a point thereon above the lower limit of travel of said cutting bit.
 4. A machine as set forth in claim 1, wherein said tool holder on said radius arm includes a tool-receiving opening therethrough, the axis of said opening being directed toward the surface of a ball held in said chuck and wherein said tool is disposed in said opening and extends therefrom towards the surface of said ball, said tool being axially movable in said tool holder opening.
 5. A machine as set forth in claim 4, wherein said tool is a cutting bit, and further including means carried by said tool holder for fixing said cutting bit relative to said tool holder to prevent axial movement of said cutting bit in said tool holder opening.
 6. A machine as set forth in claim 5 and further including a feeler gauge mounted in said frame below said horizontal axis and having an upwardly directed feeler member adapted to engage the lower surface of a ball held in said chuck at a point thereon above the lower limit of travel of said cutting bit.
 7. A machine as set forth in claim 4 wherein said tool is a finishing member and further including means resiliently biasing said tool towards the surface of a ball held in said chuck. 